Publication History

Abstract

We herein report the development of a regioselective synthetic route to [70]methanofullerenes, which have potential for application as electron acceptors in solution-processed bulk heterojunction solar cells. Sterically hindered sulfur ylide, generated in situ from their corresponding sulfonium salts in the presence of 1,8-diazabicy­clo[5.4.0]undec-7-ene (DBU) as the base, smoothly reacted with [70]fullerene to afford the α-type [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM) in high purity (up to 98%). Furthermore, we successfully demonstrated the gram-scale synthesis of [70]PCBM.